The present invention relates to orthopedics and orthodontics, and more particularly to a novel orthotic brace for providing protection, support/stabilization and rehabilitation of an injured anatomical joint. Alternatively, the orthotic brace can be used as a device to prevent injury to a joint. The orthotic brace is constructed with a novel, articulated mechanical device which, when the brace is in position, permits the joint to move through selected, limited ranges corresponding to its normal anatomical motion. The orthotic brace of the present invention may be used on virtually all major anatomical joints, such as the ankle, knee, hip, elbow, wrist, shoulder, etc. For purposes of explanation, however, discussion will be limited principally to application of the orthotic brace to the ankle joint.
The ankle joint is a complex mechanism, and its motion is a remarkable example of the intricate interplay of bone and ligaments and their protective action upon one another. The ankle may be thought of as a hinge joint, although that may be somewhat of an oversimplification. Essentially, the ankle joint permits various oval and rotational motions of the foot and combinations thereof, including inversion, eversion, plantar flexion, dorsiflexion, adduction and abduction. Generally, during active inversion, where the sole of the foot is turned to face medially or inwardly, the motion includes supination, adduction and some degree of plantar flexion. During active eversion, where the sole of the foot is turned laterally or outwardly, the motion includes pronation, abduction and dorsiflexion.
Common ankle injuries include ligament sprains and tears, and in more severe cases, fractures. In athletics, it has been found that over 80 percent of all ankle sprains are inversion injuries, occurring when an athlete runs straight ahead or cuts. The foot may suddenly turn into inversion and plantar flexion and the athlete feels a sharp pain. The mechanism of an ankle sprain involving inversion-plantar flexion usually sprains the anterior talofibular ligament, and if more severe, the calcaneofibular ligament. Occasionally, a fracture of the fibula may occur. Inversion and plantar flexion may also be accompanied by rotation. The mechanism of an eversion sprain involves motion which may tear the deltoid ligament or may produce a fracture off the tip of the medial malleolus.
An excessive dorsiflexion force may jam the talus into the mortise, and may cause a fracture of the talus. Additionally, the Achilles may be injured by the stretching forces of dorsiflexion. Plantar flexion sprains, in their pure form, are rare, inasmuch as there is usually some degree of inversion as well. Ligaments which may be injured include the lateral ligaments, tibiofibular ligaments and others.
Treatment of ankle injuries depends upon the type and severity of damage. Conventional treatment focuses on immobilizing the foot relative to the leg, and may take the form of a cast or brace. It there is excessive swelling, a period of time will be permitted to lapse before application of a cast or brace. In any event, treatment requires that motion of the foot be restricted, particularly inversion and evasion. The immobilization may promote stiffness of the tissues, and that is why rehabilitation is recommended to proceed immediately in all cases of mild-to-moderate ankle sprains and even in some cases of severe but stable sprains. The idea is to allow selected limited motion to avoid reinjury and to promote a more rapid recovery, and to prevent muscular atrophy and stiffness or loss of motion. The essential problem is to stabilize the ankle joint in some manner but permit limited motion to enhance recovery.
Conventional methods of immobilizing an ankle injury involve various forms of taping and in more severe cases, use of ankle braces. Various types of ankle braces or supports have been proposed in the prior art. An example of a pliable-type ankle brace is disclosed in U.S. Pat. No. 3,970,083 where a jacket is fitted around a person's foot and ankle and includes T-shaped stiffened regions on each side. The idea is that a support is provided which may be used for supporting the ankle joint.
An orthotic brace is disclosed in U.S. Pat. No. 4,665,904 which includes a semi-rigid leg-supporting shell for fitting around the lower leg and a semi-rigid foot-supporting shell for conforming to the shape of the foot. The foot-supporting shell is rotatably secured to the leg-supporting shell, thereby resulting in a hinged structure which permits the foot to move in plantar flexion and dorsiflexion.
There are also other types of prior art devices for stabilizing the knee after knee injuries. These devices permit rotation of a knee joint and are shown in examples such as U.S. Pat. Nos. 3,799,158, 4,614,181 and others. These patents, as well as those listed above, do not actually provide a brace which will protect, support and facilitate rehabilitation of an injured ankle joint while permitting the ankle joint to move anatomically within preselected limited ranges.
Accordingly, it is a general object of the present invention to provide an orthotic brace for promoting protection, support/stabilization and rehabilitation of an injured anatomical joint, such as the ankle, by providing a structure which will enable the ankle to move anatomically. The present invention provides an orthotic brace which stabilizes the ankle joint to a preselected degree, i.e., the orthotic brace permits selectively adjustable motion of the foot in dorsiflexion/plantar flexion and inversion/eversion.
Another object of the present invention is to provide an orthotic brace which includes first and second support means for detachably engaging the lower leg and foot, respectively, interconnected by an articulated means which enables the foot to move within a selected range to approximate anatomical motion of the ankle.
Still another object of the present invention is to provide an orthotic brace in which first adjustment means are associated with the articulated means for selectively predetermining the extent of dorsiflexion and plantar flexion. Additionally, second adjustment means are provided with the articulated means for selectively predetermining the extent of inversion and eversion.
These and other objects and advantages of the present invention will be more readily appreciated after a consideration of the attached drawings and the detailed description of the preferred embodiment.